Softener and flame-resistant coating composition, method of its application to cellulosic materials and the article produced thereby



Patented Oct. 19, 1954 NITE srrss SOFTENER AND FLAME-RESISTANT COAT- ING COMPOSITION, METHOD OF ITS AP- PLICATION T CELLULOSIC MATERIALS AND THE ARTICLE PRODUCED THEREBY David X. Klein, Montclair, and Mark N. Gurgan, Clifton, J., assignors to Heyden Chemical Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application January 16, 1951, Serial No. 206,306

( Cl. 106-15l 18 Claims. 1

This invention relates to a combined softener and fire retardant. for non-volatile, readily combustible, organic materials, relating more specifically to the reaction product used to impart softening and flame-resistant properties to textiles and cellulose materials, and to the rocess for the preparation of the aforesaid reaction product.

In imparting flame-resistant qualities to normally flammable materials such as cotton fabrics, fibrous and textile articles, and generally materials which areof a cellulosic nature, it. is highly desirable that the feel or hand of the material remain soft or substantially unaffected. While satisfactory flame-resistance and glow-resistance properties can be imparted to these products by a number of compounds which have been reported in the literature, it has been found that these compounds have proved to be unsatisfactory in one or more respects in thatthe materials treated with these substances either became stiff and discolored, or their texture was adversely affected in some other fashion. Conventional paper softeners were likewise found to be unsuitable in that they did not impart adequate flame-resisting qualities to the articles treated. Although paper that has been treated with mixtures of conventional flame-proofing compounds and papersofteners will be softened and its flame resistance increased, the combined and total effect is very slight and generally unsatisfactory. Another disadvantage associated-with the use of these mixtures is, that they tend to leave crystalline deposits on the inner surface of the paper as they dry.

This invention provides a simple method for the manufacture of asingle preparation which will impart highly satisfactory flame-resistant and softening qualities to paper, cellulose textiles, and other materials of similar nature. Another important advantage associated, with the use of this new composition is that it is nonyellowing and the articles or materials treated therewith do not become discolored. Likewise, the combined softener and flame-resistant composition is odorless and does not impart an odor to the paper or textile material when it' is impregnated with this compound.

Regarded in certain of its broader aspects, the novel features in the present invention comprise imparting flame-resistant and softening qualities to non-volatile, readily combustible, organic materials such as cellulose compositions, by treatment with the product obtained by the reaction of a dibasic acid amide, a polyhydric alcohol possessing humectant properties, and an oxide of a phosphorous compound containing hydrogen.

Dibasic acid amides within the purview of this 2 invention include urea, guanidine, succinamide, etc. and alkyl derivatives thereof.

On the application of this product to paper or cellulose fabric, the material so treated acquires substantially flame-resistant and glow-resistant properties, while at the same time retaining an excellent hand. Surprisingly, the treated materials retain their properties after exposure to changes in humidity. For example, results indicate that materials treated with the afore-mentioned reaction product are soft at a relative humidity of about 10%, and are wet but not dripping at a relative humidity of about In a more specific embodiment of this invention, a mixture containing urea, glycerin and phosphoric acid is inter-reacted at a temperature of about C. for a short eriod of time; that is, about 13 minutes, at a temperature varying between -160 C. At the end of this time, a colorimetric test for phosphate ion is used to determine the degree to which reaction has taken place.

While the proportions of the aforesaid reactants may be varied widely without appreciably affecting the softness or flame-resistant characteristics imparted by the reaction product, a ratio of between 4.4 and 8.0 mols of urea to about 1.2 mols of glycerine to about 1.0 mol of phosphoric acid is preferred. The use of larger ratios of phosphoric acid produces viscous products that are rather dificult to handle, while the use of only 1 mol of urea per mol of glycerine results in somewhat stiffer products. When a ratio of 12 mols of urea per mol of glycerine is used in preparing the combined softener and flame-resistant composition, the fabric treated with this preparation is not considered to be satisfactory because of its low resistance to charring.

The preferred temperature for the fusion of the reactants is between 130 and 160 C. Below this range of temperature, the reaction takes place very slowly and complete reaction is not affected in a reasonable length of time. At temperatures above 160 0., however, the reaction proceeds'so rapidly that it is somewhat difficult to control. Within the preferred temperature range wherein the molar ratios are about lxl mols of urea, about 1 mol of glycerine, about 1.2 mols of phosphoric acid, the reaction is 87 complete in about 3 hours at a temperature of about 130 C., 98% complete in about 3 hours at a temperature of about C., and 98% complete in about 13 minutes at a temperature of about C.

It should be mentioned that while the use of phosphoric acid is indicated in the preparation of this combined softener and flame-resistant compound, excellent results can similarly be obtained by the use of other oxides of phosphorous compounds containing hydrogen, such as dibasic ammonium phosphate, monobasic ammonium phosphate, pyrophosphoric acid, metaphosphoric acid, magnesium phosphate, etc. The use of phosphoric acid is preferred from the practical or processing point of view because it is a liquid and is easier to handle than a solid material, such as dibasic ammonium phosphate.

Although the use of glycerine in the preparation of the desired reaction products is preferred, other polyhydric alcohols which exhibit humectant properties, such as sorbitol, ethylene glycol, mannitol, etc., may likewise be used in the reaction.

Aqueous solutions of the fusion products obtained are prepared and then applied tothe cellulosic materials to be treated by the use of con ventional methods, such as spraying, immersion in baths, etc. The treated material is then heat dried.

The following example illustrates a method of carrying out the present invention but it is to be understood that this example is given by way of illustration and not of limitation.

Example The combined softener and flame-resistant compositions listed in the accompanying table were prepared by heating mixtures of urea, glycerine, and phosphoric acid at 160 C. for 13 minutes. At the end of this time, a colorimetric test for phosphate ion was used to determine the degree to which reaction had. taken place. The fusion products were diluted with water while warm until the solution was diluted to 30% and then further diluted until a aqueous solution was obtained. The 10% solution was applied to paper (the pickup was approximately 100%). The treated material was then oven dried at 60 C. and conditioned by standing overnight (before evaluation) The samples of treated paper were tested for softness by the TAPPI Rigidity, Stiffness, and softness of Paper and Paperboard Test T451 M45. The softness of paper as determined by this test is inversely proportional to the maximum length of a strip of paper that will fall from left to right through the vertical when one end of it is held between the jaws of a spindle which is rotated clockwise through an arc of 90.

The flammability characteristics of the samples were determined by the Bureau of Standards Clamp Field Test, wherein a flame is applied for twelve seconds to a piece of cloth held in a vertical position by a metal clamp. A satisfactorily flame-resistant material will neither flame for more than two seconds after the igniting flame is removed nor glow more than four seconds after the removal of the flame. The average length of char in three tests will be not more than 2 inches.

The data indicates that all the samples were considerably softer than the untreated paper and were resistant to both burning and afterglow whereas the untreated paper burned rapidly.

While the combined softener and flame-resistant compositions herein described are primarily intended for use in treating paper, excellent results are also obtained when other cellulosic materials, such as, for example, cotton or rayon fabrics, are treated with the compositions.

Various changes and modifications may be made in carrying out this invention without departing from the spirit and scope thereof. Inasmuch as these changes and modifications are within the scope of the appended claims they are to be considered as part of this invention.

We claim:

1. A combined softener and flame-resistin coating composition which comprises the interreaction product of a dibasic acid amide, an oxide of a phosphorous compound containing hydrogen, and a polyhydric alcohol possessing humectant properties inter-reacted at a temperature in the range of about -160 C.

2. A combined softener and flameuesisting coating composition which comprises the interreaction product of urea, phosphoric acid, and a polyhydric alcohol possessing humectant properties interreacted at a temperature in the range of about 130-l60 C.

3. A combined softener and flame-resisting coating composition which comprises the interreaction product of urea, dibasic ammonium phosphate, and a polyhydric alcohol possessing humectant properties inter-reacted at a temperature in the range of about 130-160 C.

l. A combined softener and flame-resisting coating composition which comprises the interreaction product of urea, an oxide of a phosphorous compound containing hydrogen, and giycerine inter-reacted at a temperature in the range of about 130-160 C.

5. A combined softener and flame-resisting coating composition which comprises the interreaction product of urea, an oxide of a phosphorous compound containing hydrogen, and sorbitol inter-reacted at a temperature in the range of about 130-160 C.

6. A combined softener and flame-resisting coating composition which comprises the interreaction product of urea, an oxide of a phosphorous compound containing hydrogen, and ethylene glycol inter-reacted at a temperature in the range of about 130-160 C.

7. A combined softener and flame-resisting coating composition which comprises the interreaction product of about 4-8 mols of urea, about 1 mol of phosphoric acid, and about 1 mol of glycerine inter-reacted at a temperature in the range of about l30-160 C.

8. A combined softener and flame-resisting Mo] Ratio in Formulation Percent Samplev Glycerme Reaction plctcness softne s,

Flammability Characteristics Char Afterlcn gth inches glow Burning Time Untreated Sample Burns Rapidly.

coating composition which comprises the interreaction product of about 4 mole of urea, about 1 mol of phosphoric acid, and about 1 mol of glycerine inter-reacted at a temperature in the range of about 13016'O C.

9. A process for imparting softness and flameresistant qualities to non-volatile, readily combustible, organic materials which comprises impregnating said materials with an aqueous solution of the inter-reaction product of a dibasic acid amide, an oxide of a phosphorous compound containing hydrogen, and a polyhydric alcohol possessing humectant properties inter-reacted at a temperature in the range of about 130-150 C.

10. A process for imparting softness and flameresistant qualities to cellulosic materials which comprises impregnating said materials with an aqueous solution of the inter-reaction product of a dibasic acid amide, an oxide of a phosphorous compound containing hydrogen, and a polyhydric alcohol possessing humectant properties interreacted at a temperature in the range of about 130-160 C.

11. A process for imparting softness and flameresistant qualities to fibrous cellulosic materials which comprises impregnating said materials with an aqueous solution of the inter-reaction product of a dibasic acid amide, an oxide of a phosphorous compound containing hydrogen, and a polyhydric alcohol possessing humectant properties inter-reacted at a temperature in the range of about 130-160 C.

12. A process for imparting flame-resistant qualities to paper which comprises impregnating said material with an aqueous solution of the inter-reaction product of a dibasic acid amide, an oxide of a phosphorous compound containing hydrogen, and a polyhydric alcohol possessing humectant properties inter-reacted at a temperature in the range of about 130-160 C.

13. A process for imparting softness and flameresistant qualities to cellulosic materials which comprises impregnating said materials with an aqueous solution of the inter-reaction product of about 4-8 mole of urea, about 1 mol of phosphoric acid, and about 1 mol of glycerine inter-reacted at a temperature in the range of about 130- 160 C.

14. A process for imparting flame-resistant qualities to paper which comprises impregnating said material with an aqueous solution of the inter-reaction product of about 4-8 mols of urea, about 1 mol of phosphoric acid, and about 1 mol of glycerine inter-reacted at a temperature in the range of about -160 C.

15. A process for imparting softness and flameresistant qualities to cellulosic materials which comprises impregnating said materials with an aqueous solution of the inter-reaction product of about 4 mole of urea, about 1 mol of phosphoric acid, and about 1 mol of glycerine inter-reacted at a temperature in the range of about 130- C.

16. A process for imparting flame-resistant qualities to paper which comprises impregnating said material with an aqueous solution of the inter-reaction product of about 4 mols of urea, about 1 mol of phosphoric acid, and about 1 mol of glycerine inter-reacted at a temperature in the range of about IMP-169 C.

17 A fibrous cellulosic material having softness and. flame-resistant qualities which comprises fibrous cellulosic material impregnated with the inter-reaction product of a dibasic acid amide, an oxide of a phosphorous compound containing hydrogen and a polyhydric alcohol possessing humectant properties inter-reacted at a temperature in the range of about 130-160 C.

18. A fibrous cellulosic material having softness and flame-resistant qualities which comprises fibrous cellulosic material impregnated with the inter-reaction product of urea, phosphoric acid, and glycerine, inter-reacted at a temperature in the range of about 130-160 0,

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,945,714 Winograclow Feb. 6, 1934 2,089,697 Grobe Aug. 10, 1937 2,997,509 Boller Nov. 2, 1937 2,347,031 Cupery Apr. 18, 1944- 2,415,112 Seymour et a1. Feb. 4, 1947 2,422,730 Hoffman June 24, 1947 ,1 1 Rosser Feb, 17, 1948 2,549,060 Creely Apr. 1'7, 1951 

1. A COMBINED SOFTENER AND FLAME-RESISTING COATING COMPOSITION WHICH COMPRISES THE INTERREACTION PRODUCT OF A DIBASIC ACID AMIDE, AN OXIDE OF A PHOSPHORUS COMPOUND CONTAINING HYDROGEN, AND A POLYHYDRIC ALCOHOL POSSESSING HUMECTANT PROPERTIES INTER-REACTED AT A TEMPERATURE IN THE RANGE OF ABOUT 130*-160* C. 